Electronic devices, such as tablets, computers, copiers, digital cameras, smart phones, control systems and automated teller machines, among others, often employ electronic components which leverage chip package assemblies for increased functionality and higher component density. Conventional chip packaging schemes often utilize a plurality of integrated circuit (IC) dice to be mounted to a single package substrate. The IC dice may include memory, logic or other IC devices.
Out of plane deformation of the chip package assembly can be problematic to conventional chip packaging schemes. In many instances, a stiffener is utilized to stiffening the chip package assembly against out of plane deformation. However, particularly in larger chip package assemblies, the stiffener itself may bend or twist, or even become delaminated from chip package assembly, thus still permitting undesirable warpage and bending during manufacture and/or use. Such warpage and bending of the chip package assembly can lead to solder connection failure or other damage to the components and devices of the chip package assembly, which may detrimentally effect device performance and reliability.
In large chip package assemblies, simply utilizing a heavy duty (e.g., “stiffer”) stiffener has not shown to be a robust solution. Particularly, heavy duty stiffeners that rigidly hold the chip package assembly extremely flat without any flexibility induce large stresses on the interconnect substrate to which the dice are mounted. Such large stresses can lead to solder connection failure or other damage to the components and devices of the chip package assembly, even if the substrate itself doesn't warp or bend. Solder connection failure is particularly problematic when lead-free solder is utilized to make the electrical connections between the interconnect substrate and dice, as lead-free solder is not a strong as the more commonly used tin-lead (Sn—Pb) solders, which have greater tensile and shear strengths.
Therefore, a need exists for an improved chip package assembly, and in particular, to a chip package assembly having an improved stiffener.